Recapping the big headlines

U.s. stocks closed little changed on Thursday afternoon, holding solid gains for the week so far, as investors digested a spate of corporate news.

CNBC's David Faber reporting Thursday afternoon that Pfizer and Allergan are in late-stage talks about a deal. The deal is thought to be in final talks despite the Treasury Department trying to crack down on tax inversions like this potential merger, that would result in Pfizer relocating from the United States to Ireland.

The two companies traded more than 2.5 percent lower to weigh on the health care sector, which dropped 1.5 percent, to become the top laggard in the S&P 500.

Shares of Gold Fields soared on a turnaround of its South African mine. The gold miner, which has been plagued by a number of technical difficulties, reported improved production and lower cash outflows, which sent shares up more than 20 percent Thursday.

The company's South Deep mine, which holds a 40-million ounces in bullion reserves, is Gold Fields' last remaining South African asset.